In the conventional process for producing an aromatic polycarbonate resin by interfacial polymerization method, monohydric phenols such as p-tert-butylphenol and phenol are usually used as terminators or molecular weight modifiers. In addition, use of fatty acid chloride and so on is known.
In the conventional process, fatty acid has not been used as such as a terminator because the fatty acid does not have sufficiently high reactivity and cannot control the molecular weight, leading to the production of high molecular weight products.
Therefore, in producing aromatic polycarbonate having fatty acid at the terminal thereof by the interfacial polymerization method, fatty acid chloride is used in place of fatty acid. Even in the conventional process using fatty acid chloride, since the fatty acid chloride contains unreacted fatty acid and further fatty acid resulting from decomposition thereof during polymerization as impurities, and the reactivity is poor as compared with the case in which monohydric phenols such as p-ter-butylphenol are used as terminators, polycarbonate not having the terminator at the terminal thereof is formed. Thus, it has been difficult to produce polycarbonate having sufficiently high heat stability.
As a result of investigations to develop a method for introducing fatty acid in the terminal of polycarbonate, it has been found that in producing an aromatic polycarbonate resin by the interfacial polymerization method, if tertiary amine is added after addition of a quaternary ammonium salt as a polymerization catalyst, the fatty acid can be introduced in the terminal of polycarbonate.